| タイトル | Steps toward determination of the size and structure of the broad-line region in active galactic nuclei. IV - Intensity variations of the optical emission lines of NGC 5548 |
| 著者（英） | Bochkarev, N. G.; Elvis, M.; Bertram, R.; Peterson, B. M.; Kollatschny, W.; Bechtold, J.; Filippenko, A. V.; Boroson, T. A.; Carone, T. E.; Dietrich, M. |
| 著者所属（英） | NASA Goddard Space Flight Center|NASA Marshall Space Flight Center |
| 発行日 | 1993-05-10 |
| 言語 | eng |
| 内容記述 | Measurements of optical emission-line flux variations based on spectra of the Seyfert galaxy NGC 5548 obtained between December 1988 and October 1989 are reported. All of the measured optical emission lines, H-alpha, H-beta, H-gamma, He I 5876, and He II 4686, exhibit the same qualitative behavior as the UV and optical continua, but with short time delays, or lags, which are different for the various lines. Cross-correlation analysis is applied to measure the lags between the various lines and the continuum. Similar lags are found with respect to the UV continuum for H-alpha and H-beta, 17 and 19 d, respectively. The lag for H-gamma is shorter (13 d), only somewhat larger than the lag measured for Ly-alpha (about 10 d). The helium lines respond to continuum variations more rapidly than the hydrogen lines, with lags of about 7 d for He II 4686 and 11 d for He I 5876. |
| NASA分類 | ASTROPHYSICS |
| レポートNO | 93A36383 |
| 権利 | Copyright |
| URI | https://repository.exst.jaxa.jp/dspace/handle/a-is/317861 |
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